Open or focus a local application

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds useful behavioral detail beyond the annotations: it explains that an existing running window is focused first, otherwise a known executable or Start Menu application is launched. It also lists supported aliases, which helps predict behavior. It does not cover failure modes for unknown applications, but the annotations already provide safety and idempotency context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences, front-loaded with the key distinction, and contains no filler. Each sentence contributes either purpose, behavior, or parameter guidance.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-parameter local application launcher with annotations and an output schema, the description is sufficient. It explains the dual focus/launch behavior, identifies the local-app scope, and gives concrete alias examples.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema fully documents the single required parameter, so the baseline is 3. The description adds value by supplying a broader set of concrete aliases such as explorer, cmd, powershell, calculator, edge, and chrome, which goes beyond the schema examples.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific action and resource: it opens or focuses a local application, either by focusing an existing window or launching a known executable/Start Menu app. This clearly distinguishes it from the browser-oriented sibling tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It identifies itself as the 'Fast path for local applications,' which gives clear context for when to use it versus browser_open. However, it does not explicitly name browser_open or state exclusions such as web URLs or unknown executables.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.